1. Field of the Invention
The present invention relates to a projecting apparatus, and more particularly to a projecting apparatus for forming the mirror image of an object on a projection plane.
2. Description of the Prior Art
A projecting apparatus forming the mirror image of an object has been employed, for example, copying apparatus involving an image transfer step.
In a conventional copier the projecting apparatus is composed of a single projecting lens system, but such copier is inevitably large because of the relatively large conjugate length of such projecting lens system. In order to overcome this drawback there has been proposed a projecting apparatus having a plurality of lens systems of a relatively small conjugate length, wherein each of said lens systems shares a portion of the object to be projected, whereby said lens systems in combination function to project the entire image of said object onto a projection plane. For example United States Patent 3,584,952 discloses a projecting apparatus having a plurality of lens systems arranged along a strip-shaped area of an original to be copied, wherein each of said lens systems is adapted to project a partial image of systems being adapted to form a partial image of said strip-shaped area onto a photosensitive member. The copying apparatus can be rendered relatively compact by the use of such projecting apparatus.
Also, British Patent Specification No. 1462085 discloses a projecting apparatus which focuses the image of an object on a mirror through an array lens system and guides the light reflected by said mirror toward a refocusing plane again through said array lens system and by a half mirror positioned between the object and said array lens system, thereby forming the mirror image of said object on said focusing plane. This apparatus is however disadvantageous due to the increased loss of light resulting from the use of said half mirror.